12 replies to this topic

[Doddyz]

HI guys,

 

I own a 2001 SUbaru B4 and was wondering besides getting my ecu remapped, How to reduce the dreaded VOD lag between the 2 turbos.

 

I have heard you can do " A line 1 or hose 1 mod" Where you put a 0.8mm restrictor pill about 2 inches down the number 1 hose on the black vacuum box,

 

Has anyone here done this?

Is it worth doing?

 

Where can i get the pill from or can i order it from Subaru?

Apparantley the Part No is 22326AA260

 

Cheers Aaron

[Chaapppppp]

Hey, I bought a 0.8mm mig welding tip and cut it in half.

haven't installed yet but should do nicely, will be using it on vac line near primary turbo.                                                                                      original vac line with pill went in the bin when my bro replaced all vac lines.

[Josh18]

I think there are supposed to be more pills. It is shown where in the TT guide but i think its for an earlier model than yours maybe.

[Chaapppppp]

yeah there are 3 other pills supposed to be in system but i believe one near primary turbo has the greatest effect as far as i've been able to dig up.

[Josh18]

Doddyz, I tried the line 1 mod on my '94 and couldn't really tell any difference to tell you the truth. The best thing that has happened with my VOD is ckeaning out the BBoD with electrical cleaner. Its still there but on a full throttle dig through the vod its almost not there. It is still annoying when you change up at 4000 revs and next gear your in the vod but that's a TT thing. Your model should be able to be mapped to make it better, I'd be going that way rather than mucking about with pills etc, from my experience anyway.

[Chaapppppp]

did line 1 mod on my '97 BD5 TT, made a good difference, boost comes on earlier in revs.

[zanzarah]

The IACV has been programmed to open early thus you end up with a larger VOID due to primary boost pressure being higher than the secondary and boost get pushed back thru it
Restrictor pill in line No1 to the IACV slows the opening speed (this is a passive process vacuum cut))
This does not affect the closing speed as this is an active process via Vacuum active.
An alternative to this is to remap (REV D)the differential pressure settings so that it opens when the boost pressures of both turbos is equal.
The other is to replace the active IACV with a in pipe passive check valve, again this will only open when the turbo boost pressures are equal

[Chaapppppp]

maybe not line 1, line going to air flow control thingy under left side of intercooler

[JonoTT]

Hey all new to the thread and i know this topic has been smashed but i need to know, iv got the 0.8mm pill in hose 2 in the bbod and the 0.8mm pill in the hose between outlet nip and t-piece on primary, now i know there is a 2.0mm pill in hose from manifold to bov and 1.5mm pill in hose that t's off that hose, my question is how important are the 2.0mm and 1.5mm pills? I have a 2002 legacy gt-b bh5 rev-d manual. Apologies for the noob question but im new to the tt, and thanks for any help.

[duncanm]

Try blocking the line with the 1.5mm pill, which bleeds off boost from the BOV control line - hose 10 mod.

 

I just stuck a big ball bearing in it.

 

See TT guide: http://www.subyclub....-to-twin-turbo/

 

Good for my RevB, much livelier at partial throttle, but cruising on the freeway is a bit touchy on the throttle.. Performance may vary on RevD

[JonoTT]

Thanks Duncanm, iv heard of the "hose 10" mod but never got around to try it. Il give this a go and report back with results 😏

[zanzarah]

https://www.tastesli...01-hose-10-mod/

[JonoTT]

👌 Zanzarah